METHOD OF MAKING GOLF BALL INCORPORATING IMPROVED POLYURETHANE MATERIALS AND RESULTING GOLF BALL

Method of making a golf ball comprising the steps of: providing a subassembly; forming about the subassembly at least one layer comprised of a thermoset polyurethane which is prepared by mixing as the essential ingredients: (i) at least one long chain soft segment polyol and/or polyamine; (ii) at least one short chain-extending-type species; (iii) at least one isocyanate; and (iv) at least one additional chain-extending-type species; wherein essential ingredients (i) and (ii) are combined (reacted/mixed) to form a first sub-mixture; followed by combining/mixing the first sub-mixture and essential ingredient (iii) to form a prepolymer second sub-mixture; followed by combining (reacting/mixing) the prepolymer second sub-mixture with essential ingredient (iv) to form the thermoset polyurethane. Essential ingredients (ii) and (iv) may differ, or in some embodiments, are the same, although the total amount of essential ingredients (ii) included is preferably greater than the total amount of essential ingredient (iv).